Patents by Inventor Per Ingvar Hellman

Per Ingvar Hellman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Cutting tools and a process for the manufacture of such tools
    Patent number: 4011108
    Abstract: The invention relates to a cutting tool containing 25-33 percent by weight of Co and certain amounts of W, Mo, C, B, Zr, Si, Mn, Cr, Ni and Fe containing normal contaminants, W + 2Mo being equal to 20-40 percent by weight, the structure of the tool consisting of a martensitic matrix having a grain size of 5-70 .mu.m, determined as austenite grain size, containing 5-15 percent by volume of an intracrystalline, very homogeneously distributed fine-disperse phase consisting of an intermetallic compound of Fe, Co, W and/or Mo and, between the grains of the base mass, 20-30 percent by volume of a primarily precipitated phase mainly consisting of the same intermetallic compound but having a predominant grain size of 1-2 .mu.m.
    Type: Grant
    Filed: January 19, 1976
    Date of Patent: March 8, 1977
    Assignee: Stora Kopparbergs Bergslags Aktiebolag
    Inventors: Per Ingvar Hellman, Bo Gunnar Klang